Texture recognition device and display device

ABSTRACT

A texture recognition device and a display device are provided. The texture recognition device includes a backlight element, configured to provide first backlight; a light constraint element, configured to perform a light divergence angle constraint process on the first backlight to obtain second backlight with a divergence angle within a preset angle range, the second backlight being transmitted to a detection object; and a photosensitive element, configured to detect the second backlight reflected by a texture of the detection object to recognize a texture image of the texture of the detection object.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of PCT/CN2019/104349 filed onSep. 4, 2019, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a texture recognitiondevice and a display device.

BACKGROUND

Fingerprint is a texture formed by concave and convex skin at an end ofhuman finger, in which a convex position is called ridge and a concaveposition is called valley. Because everyone's fingerprints aredifferent, fingerprint identification technologies have been widely usedfor identifying personal identification. Similarly, people havedeveloped palm print recognition technology.

Among many fingerprint acquisition technologies, the emergence andpopularization of an optical fingerprint acquisition technology promotesthe rapid collection and verification of fingerprints on site. However,in the process of optical fingerprint acquisition, if the incident angleof the light incident on the finger is too large, the large-angleincident light is reflected by the finger and will cause crosstalk tothe fingerprint recognition, resulting in the inability to accuratelyidentify the valleys and ridges of the fingerprint.

SUMMARY

At least one embodiment of the present disclosure provides a texturerecognition device, the texture recognition device comprises: a lightconstraint element, configured to perform a light divergence angleconstraint process on the first backlight to obtain second backlightwith a divergence angle within a preset angle range, the secondbacklight being transmitted to a detection object; and a photosensitiveelement, configured to detect the second backlight reflected by atexture of the detection object to recognize a texture image of thetexture of the detection object.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the light constraint elementcomprises a collimating film, the collimating film has a mesh structureand comprises a plurality of hollowed-out regions, and each of theplurality of hollowed-out regions is configured to transmit part firstbacklight, whose divergence angle is within the preset angle range, ofthe first backlight to obtain the second backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the plurality of hollowed-outregions are arranged in an array, and a shape of each of the pluralityof hollowed-out regions comprises a square, a rectangle, a regulartriangle, a regular hexagon, or a circle.

For example, in the texture recognition device provided by someembodiments of the present disclosure, a thickness of the collimatingfilm ranges from 400 μm to 800 μm.

For example, in the texture recognition device provided by someembodiments of the present disclosure, a size of each of the pluralityof hollowed-out regions ranges from 25 μm to 65 μm, which comprises: ina case where the shape of each of the plurality of hollowed-out regionsis a square, a side length of the square ranges from 25 μm to 65 μm; ina case where the shape of each of the plurality of hollowed-out regionsis a rectangle, a long side of the rectangle ranges from 25 μm to 65 μm,a short side of the rectangle ranges from 25 μm to 65 μm, and a lengthof the long side is greater than a length of the short side; in a casewhere the shape of each of the plurality of hollowed-out regions is aregular triangle, a side length of the regular triangle ranges from 25μm to 65 μm; in a case where the shape of each of the plurality ofhollowed-out regions is a regular hexagon, a distance between twoparallel sides of the regular hexagon ranges from 25 μm to 65 μm; and ina case where the shape of each of the plurality of hollowed-out regionsis a circle, a diameter of the circle ranges from 25 μm to 65 μm.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element comprises adirect-lit backlight light source, the direct-lit backlight light sourcecomprises a plurality of light-emitting diodes arranged in an array, andthe plurality of light-emitting diodes are configured to provide initialbacklight, and the first backlight comprises the initial backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the plurality of light-emittingdiodes are in one-to-one correspondence to the plurality of hollowed-outregions, and each of the plurality of light-emitting diodes at leastpartially overlaps with a corresponding hollowed-out region in adirection perpendicular to the collimating film.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the plurality of light-emittingdiodes comprise a plurality of sub-millimeter light-emitting diodes or aplurality of micro light-emitting diodes.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element comprisesan edge-lit backlight light source and a light guide plate, and thelight guide plate is arranged on a light exit side of the edge-litbacklight light source, the edge-lit backlight light source isconfigured to provide light source backlight, and the light sourcebacklight is transmitted through the light guide plate to obtain initialbacklight, and the first backlight comprises the initial backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element comprises afirst backlight module, the first backlight module comprises adirect-lit backlight light source, a diffusion sheet, a first prismsheet, and a second prism sheet, the diffusion sheet is on a side of thedirect-lit backlight light source close to the light constraint element,the first prism sheet is on a side of the diffusion sheet close to thelight constraint element, the second prism sheet is on a side of thefirst prism sheet close to the light constraint element, the direct-litbacklight light source is configured to provide initial backlight, theinitial backlight sequentially passes through the diffusion sheet, thefirst prism sheet, and the second prism sheet to obtain intermediatebacklight, and the first backlight comprises the intermediate backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element comprises asecond backlight module, the second backlight module comprises anedge-lit backlight light source, a light guide plate, a diffusion sheet,a first prism sheet, and a second prism sheet, the light guide plate ison a light exit side of the edge-lit backlight light source, thediffusion sheet is on a side of the light guide plate close to the lightconstraint element, the first prism sheet is on a side of the diffusionsheet close to the light constraint element, and the second prism sheetis on a side of the first prism sheet close to the light constraintelement, the edge-lit backlight light source is configured to providelight source backlight, the light source backlight sequentially passesthrough the light guide plate, the diffusion sheet, the first prismsheet, and the second prism sheet to obtain intermediate backlight, andthe first backlight comprises the intermediate backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element comprisesan edge-lit backlight light source and a light guide plate, the lightguide plate is on a light exit side of the edge-lit backlight lightsource, the light constraint element comprises an inverse prism sheet,the inverse prism sheet is on a light exit side of the light guideplate, the edge-lit backlight light source is configured to providelight source backlight, and the light source backlight is transmittedthrough the light guide plate to obtain initial backlight, and the firstbacklight comprises the initial backlight; and the inverse prism sheetis configured to cause the first backlight to be refracted to obtain thesecond backlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the light guide plate comprises afirst light incident surface, a first light reflecting surface, and afirst light exit surface, and the first light reflecting surface and thefirst light exit surface are oppositely arranged in a first direction,the first light incident surface is configured to receive the lightsource backlight, the first light reflecting surface is configured toreflect the light source backlight, and the initial backlight emits fromthe first light exit surface, the first light reflecting surfacecomprises a prism pillar structure array, the prism pillar structurearray comprises a plurality of triangular prism pillars arranged insequence along a second direction, the second direction is perpendicularto the first direction, a thickness of each of the plurality oftriangular prism pillars is less than 2.5 μm in the first direction, adistance between two adjacent triangular prism pillars ranges from 45 μmto 50 μm in the second direction, the inverse prism sheet comprises asecond light incident surface and a second light exit surface, thesecond light incident surface and the second light exit surface areoppositely arranged in the first direction, the second light incidentsurface is configured to receive the first backlight, the secondbacklight emits from the second light exit surface, the second lightincident surface comprises a prism structure array, the prism structurearray comprises a plurality of inverse prisms arranged in sequence alongthe second direction, in the first direction, a thickness of each of theplurality of inverse prisms ranges from 10 μm to 25 μm, and in thesecond direction, a distance between two adjacent inverse prisms rangesfrom 20 μm to 50 μm.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the backlight element furthercomprises a reflecting sheet, the reflecting sheet is on a side of thebacklight element away from the light constraint element, and isconfigured to reflect light incident on the reflecting sheet to obtainreflected light, and the first backlight further includes the reflectedlight.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the photosensitive elementcomprises a plurality of photosensitive sensors arranged in an array.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the plurality of photosensitivesensors are in one-to-one correspondence to the plurality ofhollowed-out regions.

For example, in the texture recognition device provided by someembodiments of the present disclosure, each of the plurality ofphotosensitive sensors comprises a light transmitting region and aphotoelectric conversion region.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the light transmitting region atleast partially surrounds the photoelectric conversion region.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the preset angle range is 0degree to 20 degrees.

For example, in the texture recognition device provided by someembodiments of the present disclosure, the texture of the detectionobject comprises a skin corresponding to a fingerprint of a user, andthe texture image comprises a fingerprint image.

At least one embodiment of the present disclosure also provides adisplay device, which comprises any one of the texture recognitiondevices provided by the above embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to clearly illustrate the technical solutions of theembodiments of the present disclosure, the drawings of the embodimentswill be briefly described in the following; and it is obvious that thedescribed drawings are only related to some embodiments of the presentdisclosure and thus are not limitative to the present disclosure.

FIG. 1A is a schematic block diagram of a texture recognition deviceprovided by embodiments of the present disclosure;

FIG. 1B is a schematic diagram showing light, whose divergence angle isoutside a preset angle range, incident on a user's skin;

FIG. 1C is a schematic diagram showing second backlight incident on auser's skin provided by embodiments of the present disclosure;

FIG. 2A is a structural schematic diagram of a texture recognitiondevice provided by embodiments of the present disclosure;

FIG. 2B is another structural schematic diagram of a texture recognitiondevice provided by embodiments of the present disclosure;

FIG. 3A is a structural schematic diagram of a collimating film in thetexture recognition device in FIG. 2A or FIG. 2B;

FIG. 3B is a schematic cross-sectional view along a line P-P′ in FIG.3A;

FIG. 4 is yet another structural schematic diagram of a texturerecognition device provided by embodiments of the present disclosure;

FIG. 5 is a structural schematic diagram of a light guide plate in thetexture recognition device shown in FIG. 4;

FIG. 6 is a structural schematic diagram of an inverse prism sheet inthe texture recognition device shown in FIG. 4;

FIG. 7 is a structural schematic diagram of a photosensitive element inthe texture recognition device shown in FIGS. 2A, 2B and 4;

FIG. 8A is another structural schematic diagram of a texture recognitiondevice provided by embodiments of the present disclosure;

FIG. 8B is another structural schematic diagram of a texture recognitiondevice provided by embodiments of the present disclosure;

FIG. 8C is a schematic diagram showing a three-dimensional structure ofa first prism sheet and a second prism sheet in the texture recognitiondevice in FIGS. 8A and 8B;

FIG. 9A is a schematic diagram of a fingerprint detected by the texturerecognition device shown in FIG. 4; and

FIG. 9B is a schematic diagram of a fingerprint detected by a texturerecognition device having a conventional backlight module.

DETAILED DESCRIPTION

In order to make objects, technical details and advantages of theembodiments of the present disclosure apparent, the technical solutionsof the embodiments will be described in a clearly and fullyunderstandable way in connection with the drawings related to theembodiments of the present disclosure. Apparently, the describedembodiments are just a part but not all of the embodiments of thepresent disclosure. Based on the described embodiments herein, thoseskilled in the art can obtain other embodiment(s), without any inventivework, which should be within the scope of the present disclosure.

Unless otherwise defined, all the technical and scientific terms usedherein have the same meanings as commonly understood by one of ordinaryskill in the art to which the present disclosure belongs. The terms“first,” “second,” etc., which are used in the present disclosure, arenot intended to indicate any sequence, amount or importance, butdistinguish various components. Also, the terms such as “a,” “an,” etc.,are not intended to limit the amount, but indicate the existence of atleast one. The terms “comprise,” “comprising,” “comprise,” “including,”etc., are intended to specify that the elements or the objects statedbefore these terms encompass the elements or the objects and equivalentsthereof listed after these terms, but do not preclude the other elementsor objects. The phrases “connect”, “connected”, etc., are not intendedto define a physical connection or mechanical connection, but maycomprise an electrical connection, directly or indirectly. “On,”“under,” “right,” “left” and the like are only used to indicate relativeposition relationship, and when the position of the object which isdescribed is changed, the relative position relationship may be changedaccordingly.

Embodiments of the present disclosure provide a texture recognitiondevice, which includes a backlight element, a light constraint element,and a photosensitive element. The backlight element is configured toprovide first backlight; the light constraint element is configured toperform a light divergence angle constraint process on the firstbacklight to obtain second backlight with a divergence angle within apreset angle range; the photosensitive element is configured to detectthe second backlight reflected by a texture of a detection object torecognize a texture image of the texture of the detection object.

In the present disclosure, the detection object can be a user, and thetexture of the detection object can be fingerprints, palm prints, etc.The following description takes the fingerprint of the user as anexample, but obviously the present disclosure is not limited to thiscase.

Texture recognition device provided by the embodiments of the presentdisclosure can use the light constraint element to restrict thedivergence angle of backlight used for texture recognition, so that theproblem of light crosstalk in the process of texture recognition can beprevented or reduced, and the accuracy of texture recognition can beimproved.

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. It should be notedthat the same or similar reference numerals in different drawings willbe used to refer to the same elements that have been described.

FIG. 1A is a schematic block diagram of a texture recognition deviceprovided by an embodiment of the present disclosure. As shown in FIG.1A, the texture recognition device 100 includes a backlight element 110,a light constraint element 120, and a photosensitive element 130.

The backlight element 110 is configured to generate first backlight. Forexample, the first backlight can be used for texture recognition, suchas fingerprint recognition, after the light constraint element 120performs the light divergence angle constraint process on the firstbacklight.

As shown in FIG. 1A, the light constraint element 120 is located on aside of the backlight element 110 close to the photosensitive element130, and is configured to perform the light divergence angle constraintprocess on the first backlight generated by the backlight element 110 toobtain second backlight with a divergence angle within a preset anglerange.

As shown in FIG. 1A, the photosensitive element 130 is located on a sideof the light constraint element 120 away from the backlight element 110,that is, the light constraint element 120 is located between thephotosensitive element 130 and the backlight element 110. The secondbacklight may be incident on the user's skin 200 and reflected by theuser's skin 200, and the photosensitive element 130 is configured todetect the second backlight reflected by the user's skin 200 to acquiretexture information of the user's skin 200, thereby identifying thetexture image of the user's skin 200.

For example, the user's skin may include a skin corresponding to usersfingerprints, the texture information of the user's skin may beinformation corresponding to the fingerprints, and the texture imageincludes the fingerprint image. For example, the users fingerprints mayinclude fingerprints, such as finger fingerprints, toe fingerprints, andthe like.

For example, the preset angle range may be an angle range of an includedangle between a light ray (e.g., the second backlight) incident on theuser's skin and a normal direction, and the normal direction may be adirection perpendicular to a plane where the photosensitive element 130is located. For example, the preset angle range can be 0˜20 degrees, forexample, 0˜15 degrees. It should be noted that the specific value of thepreset angle range can be preset according to the actual situation.

FIG. 1B is a schematic diagram showing light, whose divergence angle isoutside a preset angle range, incident on the user's skin; and FIG. 1Cis a schematic diagram showing second backlight incident on the user'sskin provided by an embodiment of the present disclosure.

For example, as shown in FIGS. 1B and 1C, the photosensitive element 130may include a plurality of photosensitive sensors, the plurality ofphotosensitive sensors constitute a photosensitive sensor array 131.Each photosensitive sensor can be an appropriate type of image sensor,for example, a glass substrate image sensor, for example, themanufacture method of the photosensitive sensor can includemanufacturing a photosensitive pixel array on a glass substrate and thencutting the photosensitive pixel array to obtain the photosensitivesensor. In the case where the user's skin 200 corresponds to the user'sfingerprint, the valley ridge period of the fingerprint is about 350microns (μm), that is, the sum of the length of one valley and thelength of one ridge is about 350 μm.

As shown in FIG. 1B, for a ridge of the fingerprint, in the case wherelight whose divergence angle is outside the preset angle range (forexample, an angle of an included angle λ₁ between the light and thenormal n is greater than 20 degrees, for example, λ₁ is 40 degrees, 50degrees, etc.) is incident on the surface of the ridge, the lightreflected by the ridge can be incident on the photosensitive sensorcorresponding to a valley adjacent to the ridge, for example, orincident on the photosensitive sensor corresponding to a ridge adjacentto the ridge, thereby causing light crosstalk and reducing contrast andrecognition accuracy.

It should be noted that “valley adjacent to the ridge” means that theridge is directly adjacent to the valley, that is, there is no ridge orvalley between them; and “ridge adjacent to the ridge” means that thereis no ridge between the two ridges, but there is a valley between thetwo ridges.

As shown in FIG. 1C, in the case where the user's skin 200 correspondsto the users fingerprint, for a ridge of the fingerprint, in the casewhere the second backlight (for example, an angle of an included angleλ₂ between the second backlight and the normal n is 15 degrees), whichis emitted from the light constraint element 120 and has a divergenceangle within the preset angle range, is incident on the surface of theridge, and the second backlight reflected by the ridge can be incidenton the photosensitive sensor corresponding to the ridge; for a valley ofthe fingerprint, in the case where the second backlight, which isemitted from the light constraint element 120 and has a divergence anglewithin the preset angle range, is incident on the surface of the valley,the second backlight reflected by the valley can be incident on thephotosensitive sensor corresponding to the valley, thereby preventinglight crosstalk and improving the contrast of texture recognition.

It should be noted that “photosensitive sensor corresponding to theridge” means a plurality of photosensitive sensors covered by anorthographic projection of the ridge on the photosensitive element 130;“photosensitive sensor corresponding to the valley” means thephotosensitive sensor covered by an orthographic projection of thevalley on the photosensitive element 130.

FIG. 2A is a structural schematic diagram of a texture recognitiondevice provided by an embodiment of the present disclosure. FIG. 2B isanother structural schematic diagram of a texture recognition deviceprovided by an embodiment of the present disclosure.

For example, in some embodiments, as shown in FIG. 2A, the backlightelement 110 includes a direct-lit backlight light source 111, the lightconstraint element 120 includes a collimating film 121, and thephotosensitive element 130 includes a plurality of photosensitivesensors, and the plurality of photosensitive sensors are arranged in aplurality of rows and columns to form a photosensitive sensor array 131.

The direct-lit backlight light source 111 is configured to generateinitial backlight, and the first backlight includes the initialbacklight, that is, the initial backlight may be a part of the firstbacklight.

The collimating film 121 is located on a side of the direct-litbacklight light source 111 close to the photosensitive sensor array 131,and is configured to transmit part first backlight, whose divergenceangle is within the preset angle range, of the first backlight to obtainthe second backlight. For example, the collimating film 121 may beconfigured to transmit part initial backlight, whose divergence angle iswithin the preset angle range, of the initial backlight to obtain a partof the second backlight.

The photosensitive sensor array 131 is located on a side of thecollimating film 121 away from the direct-lit backlight light source111, and is configured to detect the second backlight reflected by theuser's skin to recognize the texture image of the user's skin.

For example, in the case where the texture recognition is performed, theuser's skin is located on a side of the photosensitive sensor array 131away from the collimating film 121.

As shown in FIG. 2A, in some examples, the backlight element 110 mayfurther include a reflecting sheet 114, and the reflecting sheet 14 islocated on a side of the direct-lit backlight light source 111 away fromthe collimating film 121, that is, the direct-lit backlight light source111 is located between the reflecting sheet 114 and the collimating film121. For example, a light reflecting surface of the reflecting sheet 114may face the direct-lit backlight light source 111, and the reflectingsheet 114 is configured to reflect light incident on the reflectingsheet 114 to obtain reflected light, and the reflected light may betransmitted to the collimating film 121. The first backlight alsoincludes the reflected light reflected by the reflecting sheet 114, thatis, the reflected light may be a part of the first backlight. Thecollimating film 121 is also configured to transmit part reflectedlight, whose divergence angle is within the preset angle range, of thereflected light transmitted to the collimating film 121 to obtain a partof the second backlight.

It should be noted that the “light incident on the reflecting sheet 114”may include a part of the initial backlight emitted by the direct-litbacklight light source 111.

As shown in FIG. 2A, in the direction perpendicular to the lightreflecting surface of the reflecting sheet 114, that is, in a firstdirection X, the reflecting sheet 114, the direct-lit backlight lightsource 111, the collimating film 121, and the photosensitive sensorarray 131 are sequentially stacked.

As shown in FIG. 2A, the texture recognition device provided by theembodiment of the present disclosure can use the collimating film 121 toperform angle constraint process on the first backlight provided by thedirect-lit backlight light source 111, so as to obtain the secondbacklight with the divergence angle within the preset angle range. Thesmall-angle second backlight incident on the user's skin can reduce thecrosstalk among the light rays reflected by the user's skin, thusimproving the accuracy of texture recognition.

It should be noted that, in the example shown in FIG. 2A, a reflectivelayer may be provided on a side surface of the collimating film 121facing the direct-lit backlight light source 111, and the reflectivelayer may reflect part initial backlight, whose divergence angle isoutside the preset angle range, of the initial backlight onto thereflecting sheet 114, and then the part initial backlight is reflectedback to the collimating film 121 via the reflecting sheet 114, so as toimprove the light efficiency utilization ratio of the direct-litbacklight light source 111. For example, the reflective layer can bemade of a material with high reflectivity, and the reflective layer canbe made of silver, aluminum, or other materials, and is directly formedon the side surface of the collimating film 121 facing the direct-litbacklight light source 111 by, for example, a coating method. In thiscase, “light incident on the reflecting sheet 114” may also includelight reflected on the reflecting sheet 114 by the reflective layer ofthe collimating film 121.

For example, in other embodiments, as shown in FIG. 2B, the backlightelement 110 includes an edge-lit backlight light source 112 and a lightguide plate 113, the light constraint element 120 includes thecollimating film 121, and the photosensitive element 130 includes aplurality of photosensitive sensors arranged in an array, and theplurality of photosensitive sensors constitute a photosensitive sensorarray 131.

The edge-lit backlight light source 112 is configured to generate lightsource backlight, and an emitting direction of the light sourcebacklight is a second direction Y, for example, the second direction Yand the first direction X are perpendicular to each other.

The light guide plate 113 is located on a light exit side of theedge-lit backlight light source 112, that is, the edge-lit backlightlight source 112 is on a side where the light incident surface of thelight guide plate 113 is located. For example, as shown in FIG. 2B, thelight guide plate 113 and the edge-lit backlight light source 112 arearranged along the second direction Y. The light guide plate 113 isconfigured to guide a divergence direction of the light source backlightto obtain initial backlight, and the first backlight includes theinitial backlight, that is, the initial backlight may be a part of thefirst backlight. For example, the divergence direction of the initialbacklight is the first direction X.

For example, the light guide plate 113 may be a flat light guide plateor a wedge-shaped light guide plate.

The collimating film 121 is located on a side of the light guide plate113 close to the photosensitive sensor array 131, and is configured totransmit the part of the first backlight whose divergence angle iswithin the preset angle range to obtain the second backlight. Forexample, the collimating film 121 may be configured to transmit partinitial backlight, whose divergence angle is within the preset anglerange, of the initial backlight to obtain a part of the secondbacklight.

The photosensitive sensor array 131 is located on a side of thecollimating film 121 away from the light guide plate 113, and isconfigured to detect the second backlight reflected by the user's skinto recognize the texture image of the user's skin.

For example, in the case where texture recognition is performed, theuser's skin is located on a side of the photosensitive sensor array 131away from the collimating film 121.

As shown in FIG. 2B, in some examples, the backlight element 110 mayfurther include a reflecting sheet 114, and the reflecting sheet 114 islocated on the side of the light guide plate 113 away from thecollimating film 121, that is, the light guide plate 113 is locatedbetween the reflecting sheet 114 and the collimating film 121. Forexample, the light reflecting surface of the reflecting sheet 114 mayface the light guide plate 113, and the reflecting sheet 114 isconfigured to reflect light incident on the reflecting sheet 114 toobtain reflected light, the reflected light may propagate to thecollimating film 114 through the light guide plate 113. The firstbacklight also includes the reflected light after passing through thelight guide plate 113, that is, the reflected light may be a part of thefirst backlight. That is, the collimating film 121 is also configured totransmit part reflected light, whose divergence angle is within thepreset angle range, of the reflected light transmitted to thecollimating film 121 to obtain a part of the second backlight.

It should be noted that “light incident on the reflecting sheet 114” mayinclude a part of the light source backlight emitted by theside-incident backlight light source 112 and a part of the light sourcebacklight transmitted from the light guide plate 113 to the reflectingsheet 114.

As shown in FIG. 2B, the reflecting sheet 114, the light guide plate113, the collimating film 121 and the photosensitive sensor array 131are sequentially stacked in a direction perpendicular to the lightreflecting surface of the reflecting sheet 114, that is, in the firstdirection X.

It should be noted that the edge-lit backlight light source 112 in theembodiment of the present disclosure may include, for example, a linelight source or a point light source, the line light source may be acold cathode fluorescent lamp (CCFL), the point light source may be alight-emitting diode (LED), and a plurality of point light sources maybe disposed on a long printed circuit board to obtain a line lightsource as a whole. The embodiments of the present disclosure are notlimited to this case.

It should be noted that the direct-lit backlight light source 111 in theembodiment of the present disclosure may also include a cold cathodefluorescent lamp (CCFL) or a light-emitting diode (LED), etc. The LEDmay be of various types, such as micro LED (for example, the size of asingle device is below 100 μm, for example, below 50 μm) or a pluralityof sub-millimeter light-emitting diodes (MiniLEDs, compared with microLEDs, the size of a single mini LED is more than 100 μm). Theembodiments of the present disclosure are not limited thereto.

As shown in FIG. 2B, the texture recognition device provided by theembodiment of the present disclosure first uses the light guide plate113 to guide the light source backlight, which is generated by theedge-lit backlight light source 112 and diverges in the second directionY (e.g., horizontal direction), to be the initial backlight diverging inthe first direction X (e.g., vertical direction), the first backlightcomprising the initial backlight, and then uses the collimating film 121to perform angle constraint on the first backlight, so as to obtain thesecond backlight whose divergence angle is within the preset anglerange. The small-angle second backlight is incident on the user's skin,which can reduce the crosstalk among the light rays reflected by theuser's skin, thus improving the accuracy of texture recognition.

It should be noted that, in the example shown in FIG. 2B, a reflectivelayer may be provided on the side surface of the collimating film 121facing the light guide plate 113, the reflective layer may reflect partinitial backlight, whose divergence angle is outside the preset anglerange, of the initial backlight onto, for example, the reflecting sheet114, and then the part initial backlight is reflected back to thecollimating film 121 via the reflecting sheet 114, so as to improve thelight efficiency utilization rate of the edge-lit backlight light source112. For example, the reflective layer may be directly formed on theside surface of the collimating film 121 facing the light guide plate113 by a coating method. In this case, “light incident on the reflectingsheet 114” may also include light reflected on the reflecting sheet 114by the reflective layer of the collimating film 121.

FIG. 3A is an exemplary structure diagram of a collimating film in thetexture recognition device shown in FIG. 2A or FIG. 2B. FIG. 3B is aschematic cross-sectional view along a line P-P′ in FIG. 3A.

As shown in FIG. 3A, the collimating film 121 has a mesh structure andincludes a plurality of hollowed-out regions 1210, and each hollowed-outregion 1210 is configured to transmit part first backlight, whosedivergence angle is within the preset angle range, of the firstbacklight to obtain the second backlight.

For example, the plurality of hollowed-out regions 1210 are arranged inan array along the second direction Y and a third direction Z. The thirddirection Z and the second direction Y are perpendicular to each other.

For example, the plurality of hollowed-out regions 1210 in thecollimating film 121 can be uniformly distributed on the collimatingfilm 121, so that the second backlight emitted from the collimating film121 is uniformly distributed. However, the present disclosure is notlimited to this case, and the plurality of hollowed-out regions 1210 inthe collimating film 121 may also be unevenly distributed. For example,for the example, shown in FIG. 2B, in the second direction Y, a densityof the hollowed-out regions 1210 on a side of the collimating film 121close to the edge-lit backlight light source 112 may be less than adensity of the hollowed-out regions 1210 on a side of the collimatingfilm 121 away from the edge-lit backlight light source 112.

For example, the plurality of hollowed-out regions 1210 may have thesame shape, size, and the like, that is, the plurality of hollowed-outregions 1210 are the same. For example, the shape of each hollowed-outregion 1210 includes a rectangle (e.g., rectangle, square, etc.), aregular triangle, a regular hexagon, or a circle, etc. However, thepresent disclosure is not limited to this case, in some examples, atleast some hollowed-out regions of the plurality of hollowed-out regions1210 may be different, for example, the shapes or sizes of at least somehollowed-out regions are different.

For example, the size of each hollowed-out region 1210 ranges from 25 μmto 65 μm, for example, 47 μm. For example, as shown in FIG. 3A, theshape of each hollowed-out region 1210 may be a square, and a sidelength l of the square in the second direction Y ranges from 25 μm to 65μm, for example, l is 47 μm. For another example, in other examples, theshape of each hollowed-out region 1210 may be a rectangle, in this case,a long side of the rectangle ranges from 25 μm to 65 μm, a short side ofthe rectangle ranges from 25 μm to 65 μm, and a length of the long sideof the rectangle is greater than a length of the short side of therectangle, for example, the long side of the rectangle may be 47 μm. Foranother example, in other examples, the shape of each hollowed-outregion 1210 may be a circle, in this case, a diameter of the circleranges from 25 μm to 65 μm, for example, the diameter of the circle maybe 47 μm. For another example, in other examples, the shape of eachhollowed-out region 1210 may be a regular triangle, and in this case, aside length of the regular triangle may range from 25 μm to 65 μm, forexample, a side length of the regular triangle may be 47 μm. For anotherexample, in other examples, the shape of each hollowed-out region 1210may be a regular hexagon, and in this case, a distance between twoparallel sides of the regular hexagon ranges from 25 μm to 65 μm, forexample, may be 47 μm.

As shown in FIG. 3B, in the first direction X, a thickness d of thecollimating film 121 ranges from 400 μm to 800 μm, for example, is 600μm. The divergence angle ε of the second backlight obtained after thefirst backlight passes through the collimating film 121 is within thepreset angle range, and the preset angle range is 0˜20 degrees. Thedivergence angle ε of the second backlight passing through thehollowed-out region 1210 can be controlled by controlling the size ofthe hollowed-out region 1210 of the collimating film 121 and thethickness of the collimating film 121. For example, in the case wherethe size of the hollowed-out region 1210 is larger and the thickness ofthe collimating film 121 is smaller, the divergence angle of the secondbacklight passing through the hollowed-out region 1210 is larger. Itshould be noted that the size of the hollowed-out region 1210 and thethickness of the collimating film 121 can be set according to actualconditions.

It should be noted that in the collimating film 121, in the case wherethe light (e.g., first backlight, second backlight, etc.) used fortexture recognition is visible light, the hollowed-out regions 1210represent regions that the visible light can be transmitted, while thepart between adjacent hollowed-out regions 1210 (black part in FIG. 3A)represents a region that the visible light can not be transmitted; andin the case where the light (e.g., first backlight, second backlight,etc.) used for texture recognition is infrared light, etc., thehollowed-out regions 1210 represent regions that the infrared light canbe transmitted, while the part between adjacent hollowed-out regions1210 (black part in FIG. 3A) represents a region that the infrared lightcan not be transmitted. For example, the reflective layer on thecollimating film 121 may be disposed on the black part shown in FIG. 3A.

For example, in the example shown in FIG. 2A, the direct-lit backlightlight source 111 may include a plurality of light-emitting diodes, theplurality of light-emitting diodes are also arranged in an array alongthe second direction Y and the third direction Z, and are configured toprovide the initial backlight. For example, the plurality oflight-emitting diodes are in one-to-one correspondence to the pluralityof hollowed-out regions 1210 of the collimating film 121, and eachlight-emitting diode at least partially overlaps with the correspondinghollowed-out region 1210 in the direction perpendicular to thecollimating film 121, that is, in the first direction X. For example,the orthographic projection of each light-emitting diode on thecollimating film 121 is located in the corresponding hollowed-out region1210. However, the present disclosure is not limited thereto, and inother examples, each light-emitting diode may correspond to a pluralityof hollowed-out regions.

FIG. 4 is another structural schematic diagram of a texture recognitiondevice provided by an embodiment of the present disclosure.

As shown in FIG. 4, the backlight element 110 includes the edge-litbacklight light source 112 and the light guide plate 113, the lightconstraint element 120 includes an inverse prism sheet 122, and thephotosensitive element 130 includes the plurality of photosensitivesensors.

The edge-lit backlight light source 112 is configured to generate lightsource backlight, and the emitting direction of the light sourcebacklight is the second direction Y.

The light guide plate 113 is located on the light exit side of theedge-lit backlight light source 112, that is, the edge-lit backlightlight source 112 is located on the side where the light incident surfaceof the light guide plate 113 is located. For example, as shown in FIG.4, the light guide plate 113 and the edge-lit backlight light source 112are arranged along the second direction Y. The light guide plate 113 isconfigured to guide the divergence direction of the light sourcebacklight to obtain initial backlight, and the first backlight includesthe initial backlight, that is, the initial backlight may be a part ofthe first backlight. For example, the divergence direction of theinitial backlight is the first direction X.

The inverse prism sheet 122 is located on a side of the light guideplate 113 close to the photosensitive sensor array 131, for example, theinverse prism sheet 122 is on the light exit side of the light guideplate 113. The inverse prism sheet 122 is configured to refract thefirst backlight to obtain the second backlight.

The photosensitive sensor array 131 is located on a side of the inverseprism sheet 122 away from the light guide plate 113, that is, theinverse prism sheet 122 is located between the light guide plate 113 andthe photosensitive sensor array 131. The plurality of photosensitivesensors in the photosensitive sensor array 131 are configured to detectthe second backlight reflected by the user's skin to recognize thetexture image of the user's skin.

For example, in the case where texture recognition is performed, theuser's skin is located on the side of the photosensitive sensor array131 away from the inverse prism sheet 122.

In some examples, as shown in FIG. 4, the backlight element 110 mayfurther include a reflecting sheet 114, and the reflecting sheet 114 islocated on the side of the light guide plate 113 away from the inverseprism sheet 122, that is, the light guide plate 113 is located betweenthe reflecting sheet 114 and the inverse prism sheet 122. For example,the light reflecting surface of the reflecting sheet 114 may face thelight guide plate 113, and the reflecting sheet 114 is configured toreflect light incident on the reflecting sheet 114 to obtain reflectedlight, the reflected light may propagate to the inverse prism sheet 122through the light guide plate 113. The first backlight also includesreflected light after passing through the light guide plate 113, thatis, the reflected light may be a part of the first backlight. That is,the inverse prism sheet 122 is also configured to refract the reflectedlight propagating to the inverse prism sheet 122 to obtain a part of thesecond backlight.

It should be noted that “light incident on the reflecting sheet 114” mayinclude a part of the light source backlight emitted by theside-incident backlight light source 112 and a part of the light sourcebacklight transmitted from the light guide plate 113 to the reflectingsheet 114.

As shown in FIG. 4, the reflecting sheet 114, the light guide plate 113,the inverse prism sheet 122, and the photosensitive sensor array 131 aresequentially stacked in a direction perpendicular to the lightreflecting surface of the reflecting sheet 114, that is, in the firstdirection X.

As shown in FIG. 4, the texture recognition device provided by theembodiment of the present disclosure can first uses the light guideplate 113 to guide the light source backlight, which is generated by theedge-lit backlight light source 112 and diverges in the second directionY (e.g., horizontal direction), to be the initial backlight diverging inthe first direction X (e.g., vertical direction), the first backlightcomprising the initial backlight, and then uses the inverse prism sheet122 to perform angle constraint on the first backlight, so as to obtainthe second backlight whose divergence angle is within the preset anglerange. The small-angle second backlight is incident on the user's skin,which can reduce the crosstalk among the light rays reflected by theuser's skin, thus improving the accuracy of texture recognition.

FIG. 5 is a schematic structural diagram of a light guide plate in thetexture recognition device shown in FIG. 4.

As shown in FIG. 5, the light guide plate 113 includes a first lightincident surface 1131, a first light reflecting surface 1132, and afirst light exit surface 1133. The first light reflecting surface 1132and the first light exit surface 1133 are oppositely arranged in thefirst direction X, and the first light incident surface 1131 is incontact with the first light reflecting surface 1132 and the first lightexit surface 1133, respectively. The first light incident surface 1131causes the light source backlight from the side-incident backlight lightsource 112 to be incident onto the light guide plate 113. The firstlight reflecting surface 1132 reflects the light source backlightincident on the first light reflecting surface 1132 to obtain initialbacklight. The first light exit surface 1133 allows the initialbacklight to be emitted from the light guide plate 113. Here, the firstbacklight includes the initial backlight, that is, the initial backlightmay be a part of the first backlight.

As shown in FIG. 5, the first light reflecting surface 1132 includes aprism pillar structure array, and the prism pillar structure arrayincludes a plurality of triangular prism pillars 1130 arranged insequence in the second direction Y. The first light reflecting surface1132 includes a first side surface 11301 of the triangular prism pillar1130, a second side surface 11301 of the triangular prism pillar 1130,and a spacing surface 11303 between two adjacent triangular prismpillars 1130. It should be noted that in other embodiments of thepresent disclosure, the prism pillar structure array may also include aplurality of quadrangular prism pillars, pentagonal prism pillars, orother prism pillars arranged in sequence in the second direction Y,which is not limited by the embodiments of the present disclosure.

It should be noted that the first light reflecting surface 1132 canreflect the light incident on the first light reflecting surface 1132 tothe first light exit surface 1133. In this case, the backlight elementmay not be provided with a reflecting sheet. However, the presentdisclosure is not limited to this case, in some examples, the firstlight reflecting surface 1132 may not have a reflecting function. Inthis case, the backlight element may include a reflecting sheet, and thereflecting sheet is located on a side of the first light reflectingsurface 1132 away from the first light exit surface 1133, and thereflecting surface of the reflecting sheet faces the first lightreflecting surface 1132, and the light incident on the first lightreflecting surface 1132 can pass through the first light reflectingsurface 1132, can be incident on the reflecting sheet, and then can bereflected back to the light guide plate 113 by the reflecting sheet.

As shown in FIG. 5, the first direction X and the second direction Y areperpendicular to each other, and in the first direction X, the thicknessh1 of each triangular prism pillar is greater than 0 μm and less than2.5 μm; and in the second direction Y, the distance p1 between twoadjacent triangular prism pillars ranges from 45 μm to 50 μm. A firstbase angle β₁ of each triangular prism pillar ranges from 80 degrees to90 degrees, and a second base angle β₂ of each triangular prism pillarranges from 1 degree to 2.5 degrees.

In embodiments of the present disclosure, the material of the lightguide plate 113 may include plastic materials or other materials thatare easy to be processed and molded. For example, the material of thelight guide plate 113 may be at least one selected from a groupconsisting of PMMA (poly methyl meth-acrylate), PC (Polycarbonate), PI(Polyimide), PES (Polyethersulfone resin), and PET (Polyethyleneterephthalate), and the embodiments of the present disclosure are notlimited thereto.

It should be noted that the light guide plate 113 shown in FIG. 5 canalso be applied to the embodiment shown in FIG. 2B.

FIG. 6 is a structural schematic diagram of an inverse prism sheet inthe texture recognition device shown in FIG. 4.

As shown in FIG. 6, the inverse prism sheet 122 includes a second lightincident surface 1221 and a second light exit surface 1222, the secondlight incident surface 1221 and the second light exit surface 1222 areoppositely arranged in the first direction X. The second light incidentsurface 1221 is configured to receive the first backlight, that is, thefirst backlight is incident on the second light incident surface 1221and the second backlight is emitted from the second light exit surface1222.

As shown in FIG. 6, the second light incident surface 1221 includes aninverse prism structure array, and the inverse prism structure arrayincludes a plurality of inverse prisms 1220 arranged in sequence in thesecond direction Y. The second light incident surface 1221 includes afirst side surface 12201 of the inverse prism 1220 and a second sidesurface 12202 of the inverse prism 1220.

As shown in FIG. 5, the first direction X and the second direction Y areperpendicular to each other, and in the first direction X, the thicknessh2 of each inverse prism ranges from 10 μm to 25 μm: and in the seconddirection Y, the distance p2 between vertex angles of two adjacentinverse prisms ranges from 20 μm to 50 μm. The apex angle of eachinverse prism θ ranges from 60 degrees to 75 degrees.

For example, the inverse prism sheet may be a film with a prismstructure formed by covering the surface of PET (Polyethyleneterephthalate) matrix material with UV (Ultra-Violet) curable resinmaterial.

For example, each inverse prism may be a triangular prism pillar. Inother embodiments of the present disclosure, the shape of the inverseprism may also be a quadrangular prism pillar, a pentagonal prismpillar, or other prism pillar, and the embodiments of the presentdisclosure are not limited thereto.

It should be noted that in the example shown in FIG. 6, two adjacentinverse prisms in the inverse prism structure array are in directcontact with each other, but the present disclosure is not limited tothis case. In other examples, two adjacent inverse prisms in the inverseprism structure array may not be in direct contact, that is, there is acertain interval distance between two adjacent inverse prisms. In thiscase, the second light incident surface 1221 also includes a spacingsurface between two adjacent inverse prisms 1220.

FIG. 7 is a structural schematic diagram of a photosensitive element inthe texture recognition device shown in FIGS. 2A, 2B, and 4.

As shown in FIG. 7, the photosensitive element 130 includes a pluralityof photosensitive sensors 1310, and the plurality of photosensitivesensors 1310 may be arranged in an array along the second direction Yand the third direction Z.

For example, each photosensitive sensor 1310 may be a light transmittingsensor, and each photosensitive sensor 1310 includes a lighttransmitting region 1311 and a photoelectric conversion region 1312. Thelight transmitting region 1311 at least partially surrounds thephotoelectric conversion region 1312. Two adjacent photosensitivesensors 1310 are in direct contact.

For example, the light transmission region 1311 is used to transmit thesecond backlight emitted from the light constraint element 120, so thatthe second backlight can be incident on the user's skin.

For example, respective photosensitive sensors 1310 are in one-to-onecorrespondence to the plurality of hollowed-out regions 1210 of thecollimating film 121, and in the direction perpendicular to thecollimating film 121, that is, in the first direction X, the lighttransmitting region 1131 of each photosensitive sensor 1310 at leastpartially overlaps with the corresponding hollowed-out region 1210 ofthe collimating film 121, so that the second backlight transmitted fromthe hollowed-out region 1210 of the collimating film 121 can be incidenton the user's skin through the light transmitting region 1131 of thephotosensitive sensor 1310. However, the present disclosure is notlimited to this case, and in other examples, each photosensitive sensor1310 may correspond to a plurality of hollowed-out regions.

For example, the photoelectric conversion region 1312 may be providedwith a plurality of photosensitive units, the photosensitive units maybe photodiodes (PD), phototransistors, etc., and the photosensitiveunits are used to convert the second backlight reflected through theuser's skin into current signals. For finger fingerprints, because theridge lines and valley lines of finger fingerprints have differentgeometric characteristics, and the ridge lines are convex and the valleylines are concave, in a case where the ridge lines and the valley linesare illuminated by light (e.g., the second backlight), the reflectionintensity of the ridge lines to light is different from the reflectionintensity of the valley lines to light, resulting in that currentsignals obtained by respective photosensitive sensors 1310 in thephotosensitive element 130 are also different. By detecting themagnitudes of the current signals, fingerprint recognition can beachieved.

For example, as shown in FIG. 7, an exemplary shape of the lighttransmitting region 1311 may be a concave shape so as to partiallysurround the photoelectric conversion region 1312. Or, the lighttransmitting region 1311 may have other shapes, such as I-shape or thelike.

It should be noted that the embodiments of this present disclosure arenot limited to this case. In other examples, each photosensitive sensormay only include a photoelectric conversion region, and the plurality ofphotosensitive sensors are arranged at intervals, that is, there is acertain interval between adjacent photosensitive sensors, and theinterval region between adjacent photosensitive sensors can be used totransmit the second backlight emitted from the light constraint element120, so that the second backlight can be incident on the user's skin.

FIG. 8A is another structural schematic diagram of a texture recognitiondevice provided by an embodiment of the present disclosure. FIG. 8B isanother structural schematic diagram of a texture recognition deviceprovided by an embodiment of the present disclosure.

As shown in FIG. 8A, the backlight element 110 may include a firstbacklight module, the first backlight module may include a direct-litbacklight light source 111, a diffusion sheet 115, a first prism sheet116, and a second prism sheet 117. The light constraint element 120includes a collimating film 121; the photosensitive element 130 includesa plurality of photosensitive sensors, and the plurality ofphotosensitive sensors are arranged in a plurality of rows and columnsto constitute a photosensitive sensor array 131.

The direct-lit backlight light source 111 is configured to generateinitial backlight.

The diffusion sheet 115 is located on a side of the direct-lit backlightlight source 111 close to the collimating film 121, and is configured tosufficiently scatter the initial backlight from the direct-lit backlightlight source 111.

The first prism sheet 116 is located on a side of the diffusion sheet115 close to the collimating film 121, that is, the first prism sheet116 is located between the diffusion sheet 115 and the collimating film121. The second prism sheet 117 is located on a side of the first prismsheet 116 close to the collimating film 121, that is, the second prismsheet 117 is located between the first prism sheet 116 and thecollimating film 121. The first prism sheet 116 and the second prismsheet 117 are configured to gather the initial backlight emitted fromthe diffusion sheet 115 to obtain intermediate backlight, and thedivergence angle of the initial backlight is greater than the divergenceangle of the intermediate backlight. The first backlight includes theintermediate backlight, that is, the intermediate backlight may be apart of the first backlight.

The collimating film 121 is located on a side of the second prism sheet117 close to the photosensitive sensor array 131, and is configured totransmit part first backlight, whose divergence angle is within thepreset angle range, of the first backlight to obtain the secondbacklight. For example, the collimating film 121 may be configured totransmit part intermediate backlight, whose divergence angle is withinthe preset angle range, of the intermediate backlight to obtain a partof the second backlight.

The photosensitive sensor array 131 is located on the side of thecollimating film 121 away from the second prism sheet 117, and isconfigured to detect the second backlight reflected by the user's skinto recognize the texture image of the user's skin.

For example, in the case where texture recognition is performed, theuser's skin is located on the side of the photosensitive sensor array131 away from the collimating film 121.

As shown in FIG. 8A, in some examples, the first backlight module mayfurther include a reflecting sheet 114, and the reflecting sheet 114 islocated on a side of the direct-lit backlight light source 111 away fromthe diffusion sheet 115, that is, the direct-lit backlight light source111 is located between the reflecting sheet 114 and the diffusion sheet115. For example, a light reflecting surface of the reflecting sheet 114may face the direct-lit backlight light source 111, and the reflectingsheet 114 is configured to reflect the light incident on the reflectingsheet 114 to obtain reflected light, the reflected light may propagateto the collimating film through the diffusion sheet 115, the first prismsheet 116, and the second prism sheet 117 in sequence. The firstbacklight also includes the reflected light after passing through thediffusion sheet 115, the first prism sheet 116, and the second prismsheet 117, that is, the reflected light is a part of the firstbacklight. That is, the collimating film 121 is also configured totransmit part reflected light, whose divergence angle is within thepreset angle range, of the reflected light transmitted to thecollimating film 121 to obtain a part of the second backlight.

It should be noted that the “light incident on the reflecting sheet 114”may include a part of the initial backlight emitted by the direct-litbacklight light source 111 and a part of the initial backlight scatteredby the diffusion sheet 115 to the reflecting sheet 114.

As shown in FIG. 8A, in the direction perpendicular to the lightreflecting surface of the reflecting sheet 114, that is, in the firstdirection X, the reflecting sheet 114, the direct-lit backlight lightsource 111, the diffusion sheet 115, the first prism sheet 116, thesecond prism sheet 117, the collimating film 121, and the photosensitivesensor array 131 are sequentially stacked.

As shown in FIG. 8B, the backlight element 110 may include a secondbacklight module, the second backlight module may include an edge-litbacklight light source 112, a light guide plate 113, a diffusion sheet115, a first prism sheet 116, and a second prism sheet 117. The lightconstraint element 120 includes a collimating film 121; and thephotosensitive element 130 includes a plurality of photosensitivesensors, and the plurality of photosensitive sensors are arranged in aplurality of rows and columns to constitute a photosensitive sensorarray 131.

The edge-lit backlight light source 112 is configured to generate lightsource backlight, and an emitting direction of the light sourcebacklight is the second direction Y.

The light guide plate 113 is located on a light exit side of theedge-lit backlight light source 112, that is, the edge-lit backlightlight source 112 is disposed on a light incident side of the light guideplate 113. For example, as shown in FIG. 8B, the light guide plate 113and the edge-lit backlight light source 112 are arranged along thesecond direction Y. The light guide plate 113 is configured to guide thedivergence direction of the light source backlight to obtain the initialbacklight. For example, the divergence direction of the initialbacklight is the first direction X.

The diffusion sheet 115 is located on a side of the light guide plate113 close to the collimating film 121, that is, the diffusion sheet 115is located between the light guide plate 113 and the collimating film121, and is configured to sufficiently scatter the initial backlightemitted from the light guide plate 113.

The first prism sheet 116 is located on a side of the diffusion sheet115 close to the collimating film 121, that is, the first prism sheet116 is located between the diffusion sheet 115 and the collimating film121. The second prism sheet 117 is located on a side of the first prismsheet 116 close to the collimating film 121, that is, the second prismsheet 117 is located between the first prism sheet 116 and thecollimating film 121. The first prism sheet 116 and the second prismsheet are configured to gather the initial backlight emitted from thediffusion sheet 115 to obtain the intermediate backlight, and thedivergence angle of the initial backlight is greater than the divergenceangle of the intermediate backlight. The first backlight includes theintermediate backlight, and the intermediate backlight may be a part ofthe first backlight.

The collimating film 121 is located on a side of the second prism sheet117 close to the photosensitive sensor array 131, and is configured totransmit part first backlight, whose divergence angle is within thepreset angle range, of the first backlight to obtain the secondbacklight. For example, the collimating film 121 may be configured totransmit part intermediate backlight, whose divergence angle is withinthe preset angle range, of the intermediate backlight to obtain a partof the second backlight.

The photosensitive sensor array 131 is located on a side of thecollimating film 121 away from the second prism sheet 117, and isconfigured to detect the second backlight reflected by the user's skinto recognize the texture image of the user's skin.

For example, in the case where texture recognition is performed, theuser's skin is located on a side of the photosensitive sensor array 131away from the collimating film 121.

As shown in FIG. 8B, in some examples, the second backlight module mayfurther include a reflecting sheet 114, and the reflecting sheet 114 islocated on a side of the light guide plate 113 away from the diffusionsheet 115, that is, the light guide plate 113 is located between thereflecting sheet 114 and the diffusion sheet 115. For example, the lightreflecting surface of the reflecting sheet 114 may face the light guideplate 113, and the reflecting sheet 114 is configured to reflect thelight incident on the reflecting sheet 114 to obtain the reflectedlight, and the reflected light can propagate to the collimating filmthrough the light guide plate 113, the diffusion sheet 115, the firstprism sheet 116, and the second prism sheet 117. The first backlightalso includes the reflected light after passing through the light guideplate 113, the diffusion sheet 115, the first prism sheet 116, and thesecond prism sheet 117, that is, the reflected light may be a part ofthe first backlight. That is, the collimating film 121 is alsoconfigured to transmit part reflected light, whose divergence angle iswithin the preset angle range, of the reflected light transmitted to thecollimating film 121 to obtain a part of the second backlight.

It should be noted that “light incident on the reflecting sheet 114” mayinclude a part of the light source backlight emitted by theside-incident backlight light source 112 and a part of the light sourcebacklight transmitted from the light guide plate 113 to the reflectingsheet 114.

As shown in FIG. 8B, the reflecting sheet 114, the light guide plate113, the diffusion sheet 115, the first prism sheet 116, the secondprism sheet 117, the collimating film 121, and the photosensitive sensorarray 131 are sequentially stacked in the direction perpendicular to thelight reflecting surface of the reflecting sheet 114, that is, in thefirst direction X.

As shown in FIG. 8A and FIG. 8B, the texture recognition device providedby the embodiment of the present disclosure can use the collimating filmto perform angle constraint on the first backlight provided by theconventional backlight module (i.e., the first backlight module and thesecond backlight module), so as to obtain the second backlight with thedivergence angle within the preset angle range. The small-angle secondbacklight is incident on the user's skin, which can reduce the crosstalkbetween the light rays reflected by the user's skin, thus improving theaccuracy of texture recognition.

FIG. 8C is a schematic diagram showing a three-dimensional structure ofa first prism sheet and a second prism sheet in the texture recognitiondevice shown in FIGS. 8A and 8B.

As shown in FIG. 8C, the first prism sheet 116 and the second prismsheet 117 may be disposed crosswise. For example, the structure of thefirst prism sheet 116 and the structure of the second prism sheet 117may be the same. Taking the second prism sheet 117 as an example, anangle of a prism vertex angle of the second prism sheet 117 may rangefrom 90 degrees to 110 degrees, and a distance between two adjacentprisms may range from 24 μm to 110 μm. It should be noted that in theembodiment of the present disclosure, the diffuser 115, the first prismsheet 116, the second prism sheet 117, etc. can refer to the design inthe conventional backlight module, and repeated portions will not bedescribed in detail here.

In an embodiment of the present disclosure, the material of thediffusion sheet 115 may include plastic materials or other materialswhich are easy to be processed and formed. For example, the material ofthe diffusion sheet 115 may be at least one selected from a groupconsisting of PMMA (poly methyl methacrylate), PC (polycarbonate), PI(polyimide), PES (polyethersulfone resin), and PET (polyethyleneterephthalate), and the embodiments of the present disclosure are notlimited thereto.

FIG. 9A is a schematic diagram of a fingerprint detected by the texturerecognition device shown in FIG. 4 according to the present disclosure,and FIG. 9B is a schematic diagram of a fingerprint detected by thetexture recognition device using a conventional backlight module.

After testing, as shown in FIG. 9A, a contrast ratio of the fingerprintdetected by the texture recognition device shown in FIG. 4 according tothe present disclosure is 1.29; as shown in FIG. 9B, a contrast ratio ofthe fingerprint detected by the texture recognition device using aconventional backlight module (hereinafter referred to as “conventionaltexture recognition device”) is 1.17, that is, the texture recognitiondevice provided by the embodiment of the present disclosure can improvethe contrast ratio of texture recognition, thereby improving theprecision of texture recognition. For example, the formula of thecontrast ratio is: the contrast ratio=gray value of the ridge/gray valueof the valley. It should be noted that “the gray value of the ridge” canrepresent an average value of a plurality of gray values of a pluralityof ridges, and “the gray value of the valley” can represent an averagevalue of a plurality of gray values of a plurality of valleys.

In order to verify the influence of reducing the angle of incident lighton texture recognition, the light tools software can be used forsimulation. Tables 1 and 2 show the results of a plurality offingerprint recognition by simulating 100 million light rays.

Table 1 is a table of fingerprint contrast ratios obtained in the casewhere fingerprint recognition is performed by using second backlightwith different divergence angles.

TABLE 1 Divergence angle 60° 30° 15° 1° \ valley ridge valley ridgevalley ridge valley ridge Gray value 0.069 0.075 0.071 0.079 0.070 0.0790.064 0.089 Contrast ratio 1.08 1.11 1.23 1.39

As shown in the data in Table 1, in the case where the divergence angleof the second backlight incident on the fingerprint skin of the user is60 degrees, the contrast ratio of the detected fingerprint image is1.08; in the case where the divergence angle of the second backlightincident on the fingerprint skin of the user is 60 degrees, the contrastratio of the detected fingerprint image is 1.08; in the case where thedivergence angle of the second backlight incident on the fingerprintskin of the user is 30 degrees, the contrast ratio of the detectedfingerprint image is 1.11; and in the case where the divergence angle ofthe second backlight incident on the fingerprint skin of the user is 15degrees, the contrast ratio of the detected fingerprint image is 1.23;and in the case where the divergence angle of the second backlightincident on the fingerprint skin of the user is 1 degree, the contrastratio of the detected fingerprint image is 1.39.

It can be seen from the data in Table 1 above that the smaller thedivergence angle of the second backlight is, the higher the contrastratio of the fingerprint image is, that is, the divergence angle of thebacklight emitted by the light source can be reduced by using the lightconstraint element, so as to achieve the purpose of improving thecontrast.

Table 2 is a table of fingerprint contrast ratios obtained in the casewhere fingerprint recognition is performed using the texture recognitiondevice of the present disclosure and the conventional texturerecognition device.

TABLE 2 Ridge Valley Average (the amount (the amount Contrast contrastof gray values) of gray values) ratio ratio Texture 21672 19824 1.091.14 recognition device 22985 19825 1.16 of the present 22961 19691 1.17disclosure Conventional 43684 39252 1.11 1.06 texture 40393 38467 1.05recognition device 41432 40245 1.03

For example, the experimental data in Table 2 are obtained by repeatinga plurality of tests under the same experimental condition. As shown inthe data in Table 2, in the case where the texture recognition deviceprovided by the embodiment of the present disclosure is used to performtexture recognition, the contrast ratio of the detected fingerprintimage is high, for example, an average contrast ratio of fingerprintsobtained by three experiments is 1.14, and in the case where theconventional texture recognition device is used to perform texturerecognition, the contrast ratio of the detected fingerprint image islow, for example, an average contrast ratio of fingerprints obtained bythree experiments is 1.06.

It can be seen from the data in Table 2 above that compared with theconventional fingerprint recognition device, the fingerprint recognitiondevice provided by the present disclosure can significantly improve thecontrast ratio of the detected fingerprint image. According to thetexture recognition device provided by the embodiment of the presentdisclosure, the light constraint element can be used to perform theangle constraint on the first backlight provided by the backlightelement, so that the second backlight with the divergence angle withinthe preset angle range can be obtained, and the crosstalk between lightrays reflected by the user's skin can be reduced in the case where thesecond backlight having a small angle is incident on the user's skin, sothat the precision of the texture recognition can be improved.

The embodiment of the present disclosure also provides a display device,the display device comprises the texture recognition device provided byany one embodiment of the present disclosure. The display devicecomprises a display region and a peripheral region located outside thedisplay region, and the texture recognition device can be disposed inthe peripheral region or in the display region.

For example, the display device may also include a display panel, andthe backlight element in the texture recognition device may be furtherlocated on a light incident side of the display panel, thereby providingthe display panel with, for example, light for display.

For example, the display panel may be a liquid crystal display panel, anelectronic paper display panel, or other types of panels with displayfunctions, and the embodiments of the present disclosure are not limitedto this case.

The display device in the embodiments of the present disclosure can beany product or component with a display function, such as a liquidcrystal panel, a liquid crystal TV, a display, an OLED panel, an OLEDTV, an electronic paper, a mobile phone, a tablet computer, a notebookcomputer, a digital photo frame, a navigator, and the like. The displaydevice may also include other conventional components, such as a displaypanel, and the embodiments of the present disclosure are not limitedthereto.

The display device provided by the embodiments of the present disclosurehas the same or similar beneficial effects as the texture recognitiondevice provided by the foregoing embodiments of the present disclosure.For the detailed description and technical effects of the display deviceprovided by the embodiment of the present disclosure, reference may bemade to the corresponding description in the embodiments of the texturerecognition device, and the repeating portions will not be repeatedhere.

For the present disclosure, the following points need to be explained:

(1) The drawings of the embodiments of the present disclosure only referto the structures related to the embodiments of the present disclosure,and other structures may refer to the general design.

(2) In case of no conflict, the embodiments of the present disclosureand the features in the embodiments can be combined with each other toobtain new embodiments.

What have been described above merely are specific implementations ofthe present disclosure, but the protective scope of the presentdisclosure is not limited to this case. The protective scope of thepresent disclosure is determined by the protection scope of the appendedclaims.

What is claimed is:
 1. A texture recognition device, comprising: abacklight element, configured to provide first backlight; a lightconstraint element, configured to perform a light divergence angleconstraint process on the first backlight to obtain second backlightwith a divergence angle within a preset angle range, wherein the secondbacklight is transmitted to a detection object; and a photosensitiveelement, configured to detect the second backlight reflected by atexture of the detection object to recognize a texture image of thetexture of the detection object; wherein the light constraint elementcomprises a collimating film, the collimating film has a mesh structureand comprises a plurality of hollowed-out regions, and each of theplurality of hollowed-out regions is configured to transmit part firstbacklight, whose divergence angle is within the preset angle range, ofthe first backlight to obtain the second backlight, the backlightelement comprises a direct-lit backlight light source, the direct-litbacklight light source comprises a plurality of light-emitting diodesarranged in an array, the plurality of light-emitting diodes are inone-to-one correspondence to the plurality of hollowed-out regions, andeach of the plurality of light-emitting diodes at least partiallyoverlaps with a corresponding hollowed-out region in a directionperpendicular to the collimating film.
 2. The texture recognition deviceaccording to claim 1, wherein the plurality of hollowed-out regions arearranged in an array, and a shape of each of the plurality ofhollowed-out regions comprises a square, a rectangle, a regulartriangle, a regular hexagon, or a circle.
 3. The texture recognitiondevice according to claim 2, wherein a thickness of the collimating filmranges from 400 μm to 800 μm.
 4. The texture recognition deviceaccording to claim 2, wherein a size of each of the plurality ofhollowed-out regions ranges from 25 μm to 65 μm, in a case where theshape of each of the plurality of hollowed-out regions is a square, aside length of the square ranges from 25 μm to 65 μm; in a case wherethe shape of each of the plurality of hollowed-out regions is arectangle, a long side of the rectangle ranges from 25 μm to 65 μm, ashort side of the rectangle ranges from 25 μm to 65 μm, and a length ofthe long side is greater than a length of the short side; in a casewhere the shape of each of the plurality of hollowed-out regions is aregular triangle, a side length of the regular triangle ranges from 25μm to 65 μm; in a case where the shape of each of the plurality ofhollowed-out regions is a regular hexagon, a distance between twoparallel sides of the regular hexagon ranges from 25 μm to 65 μm; and ina case where the shape of each of the plurality of hollowed-out regionsis a circle, a diameter of the circle ranges from 25 μm to 65 μm.
 5. Thetexture recognition device according to claim 1, wherein the pluralityof light-emitting diodes are configured to provide initial backlight,and the first backlight comprises the initial backlight.
 6. The texturerecognition device according to claim 1, wherein the plurality oflight-emitting diodes comprise a plurality of sub-millimeterlight-emitting diodes or a plurality of micro light-emitting diodes. 7.The texture recognition device according to claim 1, wherein thebacklight element comprises a first backlight module, the firstbacklight module comprises the direct-lit backlight light source, adiffusion sheet, a first prism sheet, and a second prism sheet, thediffusion sheet is on a side of the direct-lit backlight light sourceclose to the light constraint element, the first prism sheet is on aside of the diffusion sheet close to the light constraint element, andthe second prism sheet is on a side of the first prism sheet close tothe light constraint element, the direct-lit backlight light source isconfigured to provide initial backlight, the initial backlightsequentially passes through the diffusion sheet, the first prism sheet,and the second prism sheet to obtain intermediate backlight, and thefirst backlight comprises the intermediate backlight.
 8. The texturerecognition device according to claim 1, wherein the backlight elementfurther comprises a reflecting sheet, the reflecting sheet is on a sideof the backlight element away from the light constraint element, and isconfigured to reflect light incident on the reflecting sheet to obtainreflected light, and the first backlight further comprises the reflectedlight.
 9. The texture recognition device according to claim 1, whereinthe photosensitive element comprises a plurality of photosensitivesensors arranged in an array, and the plurality of photosensitivesensors are in one-to-one correspondence to the plurality ofhollowed-out regions.
 10. The texture recognition device according toclaim 9, wherein each of the plurality of photosensitive sensorscomprises a light transmitting region and a photoelectric conversionregion.
 11. The texture recognition device according to claim 10,wherein the light transmitting region at least partially surrounds thephotoelectric conversion region.
 12. The texture recognition deviceaccording to claim 1, wherein the preset angle range is 0 degree to 20degrees.
 13. The texture recognition device according to claim 1,wherein the texture of the detection object comprises a skincorresponding to a fingerprint of a user, and the texture imagecomprises a fingerprint image.
 14. A display device, comprising thetexture recognition device according to claim
 1. 15. A texturerecognition device, comprising: a backlight element, configured toprovide first backlight; a light constraint element, configured toperform a light divergence angle constraint process on the firstbacklight to obtain second backlight with a divergence angle within apreset angle range, wherein the second backlight is transmitted to adetection object; a photosensitive element, configured to detect thesecond backlight reflected by a texture of the detection object torecognize a texture image of the texture of the detection object;wherein the light constraint element comprises a collimating film, thecollimating film has a mesh structure and comprises a plurality ofhollowed-out regions, and each of the plurality of hollowed-out regionsis configured to transmit part first backlight, whose divergence angleis within the preset angle range, of the first backlight to obtain thesecond backlight, wherein the backlight element comprises a secondbacklight module, the second backlight module comprises an edge-litbacklight light source, a light guide plate, a diffusion sheet, a firstprism sheet, and a second prism sheet, the light guide plate is on alight exit side of the edge-lit backlight light source, the diffusionsheet is on a side of the light guide plate close to the lightconstraint element, the first prism sheet is on a side of the diffusionsheet close to the light constraint element, and the second prism sheetis on a side of the first prism sheet close to the light constraintelement, the edge-lit backlight light source is configured to providelight source backlight, the light source backlight sequentially passesthrough the light guide plate, the diffusion sheet, the first prismsheet, and the second prism sheet to obtain intermediate backlight, andthe first backlight comprises the intermediate backlight.
 16. A texturerecognition device, comprising: a backlight element, configured toprovide first backlight; a light constraint element, configured toperform a light divergence angle constraint process on the firstbacklight to obtain second backlight with a divergence angle within apreset angle range, wherein the second backlight is transmitted to adetection object; a photosensitive element, configured to detect thesecond backlight reflected by a texture of the detection object torecognize a texture image of the texture of the detection object;wherein the backlight element comprises an edge-lit backlight lightsource and a light guide plate, the light guide plate is on a light exitside of the edge-lit backlight light source, the light constraintelement comprises an inverse prism sheet, the inverse prism sheet is ona light exit side of the light guide plate, the edge-lit backlight lightsource is configured to provide light source backlight, and the lightsource backlight is transmitted through the light guide plate to obtaininitial backlight, and the first backlight comprises the initialbacklight; and the inverse prism sheet is configured to cause the firstbacklight to be refracted to obtain the second backlight.
 17. Thetexture recognition device according to claim 16, wherein the lightguide plate comprises a first light incident surface, a first lightreflecting surface, and a first light exit surface, and the first lightreflecting surface and the first light exit surface are oppositelyarranged in a first direction, the first light incident surface isconfigured to receive the light source backlight, the first lightreflecting surface is configured to reflect the light source backlight,and the initial backlight emits from the first light exit surface, thefirst light reflecting surface comprises a prism pillar structure array,the prism pillar structure array comprises a plurality of triangularprism pillars arranged in sequence along a second direction, the seconddirection is perpendicular to the first direction, a thickness of eachof the plurality of triangular prism pillars is less than 2.5 μm in thefirst direction, a distance between two adjacent triangular prismpillars ranges from 45 μm to 50 μm in the second direction, the inverseprism sheet comprises a second light incident surface and a second lightexit surface, the second light incident surface and the second lightexit surface are oppositely arranged in the first direction, the secondlight incident surface is configured to receive the first backlight, thesecond backlight emits from the second light exit surface, the secondlight incident surface comprises a prism structure array, the prismstructure array comprises a plurality of inverse prisms arranged insequence along the second direction, in the first direction, a thicknessof each of the plurality of inverse prisms ranges from 1 μm to 25 μm,and in the second direction, a distance between two adjacent inverseprisms of the plurality of inverse prisms ranges from 20 μm to 50 μm.18. The texture recognition device according to claim 16, wherein thephotosensitive element comprises a plurality of photosensitive sensorsarranged in an array.